1. Technical Field
The present invention relates to a display driver, an electro-optical device, an electrical apparatus, and the like.
2. Related Art
Phase expansion driving that sequentially drives a predetermined number (several to several tens) of source lines at a time is known as a driving method for electro-optical panels. In an electro-optical panel driven by the phase expansion driving, sampling sections are provided for each predetermined number of source lines. The source lines are then driven sequentially at the predetermined number of lines at a time by the sampling section performing sampling operations sequentially (for example, from left to right along the electro-optical panel) based on an enable signal output by a display driver.
Technology related to the phase expansion driving is, for example, described in JP-A-2006-227468. In JP-A-2006-227468, the electro-optical panel includes a detection circuit that detects a delay time of a sampling signal (enable signal) with respect to a data signal. A scanning control circuit then controls so that the generation timing of the sampling signal becomes earlier as the detected delay time lengthens.
In phase expansion driving, many sampling sections are provided in parallel running along a horizontal scanning direction of an electro-optical panel, and a delay amount of an enable signal differs between the left end and the right end of the electro-optical panel (the start and end of a horizontal scanning period), since signal lines of the enable signal are disposed along the same direction. Therefore, the relative timings of an active period of the enable signal and an output period of the data signal in each sampling section may differ between the left end and the right end of the electro-optical panel. In such cases, there is a possibility that the actual driving times of the source lines at the left end and the right end of the electro-optical panel may differ, leading to a possibility that this may lower the display quality.
For example, although recently the driving times per pixel have been shortened due to advances in increasingly high resolution electro-optical panels, the driving time per pixel decreases considerably as the resolution is made higher, since the number of pixel that can be driven at once by phase expansion driving is from several pixels to several tens of pixels. When doing so, the output period of the data signal is exceedingly short, and the delay of the enable signal such as that described above therefore has a relatively large influence, making it difficult to constrain the active period of the enable signal to within the output period of the data signal at both the left end and the right end of the electro-optical panel.
Note that in JP-A-2006-227468, described above, resistance and capacitance are added to the signal lines that supply the enable signal to control the delay time of the enable signal overall. Namely, the delay time of the enable signal (within the horizontal scanning period) is not controlled in respective sampling sections of the electro-optical panel.